Bi-directional cannula feature capture mechanism

ABSTRACT

A bi-directional cannula feature capture mechanism is described herein. Generally, the capture mechanism comprises an inner housing, an outer housing, and a cannula. The inner housing comprises a proximal and a distal cannula feature mating component. The outer housing is adapted to slidably receive the inner housing in a proximal direction. Additionally, the cannula extends through the inner housing and the cannula&#39;s feature has a proximal engagement and a distal engagement. The proximal and distal engagements are respectively configured to irreversibly engage the proximal and distal cannula feature mating components when the cannula tip is moved into a shielded position.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/939,575, filed Jul. 11, 2013, entitled BI-DIRECTIONAL CANNULA FEATURECAPTURE MECHANISM which is a continuation-in-part of U.S. patentapplication Ser. No. 12/396,289, filed Mar. 2, 2009, entitledBI-DIRECTIONAL CANNULA FEATURE CAPTURE MECHANISM, and are incorporatedherein by reference.

BACKGROUND OF THE INVENTION

This disclosure relates generally to vascular access devices andassociated methods. More specifically, this disclosure discusses abi-directional cannula feature capture mechanism that is adapted tocapture a cannula feature in a manner that locks the cannula in ashielded position. The bi-directional cannula feature capture mechanismcan be used with catheter assemblies.

Generally, vascular access devices are used for communicating fluid withthe vascular system of patients. For example, catheters are used forinfusing fluid (e.g., saline solution, medicaments, and/or totalparenteral nutrition) into a patient, withdrawing fluids (e.g., blood)from a patient, and/or monitoring various parameters of the patient'svascular system.

Intravenous (IV) catheter assemblies are among the various types ofvascular access devices. Over-the-needle peripheral IV catheters are acommon IV catheter configuration. As its name implies, anover-the-needle catheter is mounted over an introducer needle having asharp distal tip. The introducer needle is generally a hypodermic needlecoupled to a needle assembly to help guide the needle and to facilitateits cooperation with the catheter. At least the inner surface of thedistal portion of the catheter tightly engages the outer surface of theneedle to prevent peelback of the catheter and, thereby, facilitateinsertion of the catheter into the blood vessel. The catheter and theintroducer needle are often assembled so that the distal tip of theintroducer needle extends beyond the distal tip of the catheter.Moreover, the catheter and needle are often assembled so that, duringinsertion, the bevel of the needle faces up, away from the patient'sskin. The catheter and introducer needle are generally inserted at ashallow angle through the patient's skin into a blood vessel.

In order to verify proper placement of the needle and/or catheter in theblood vessel, the operator generally confirms that there is “flashback”of blood into a flashback chamber associated with the needle assembly.Flashback generally entails the appearance of a small amount of blood,which is visible within the needle assembly or between the needle andthe catheter. Once proper placement of the distal tip of the catheterinto the blood vessel is confirmed, the operator may apply pressure tothe blood vessel by pressing down on the patient's skin over the bloodvessel, distal to the introducer needle and the catheter. This fingerpressure momentarily occludes the vessel, minimizing further blood flowthrough the introducer needle and the catheter.

The operator may then withdraw the introducer needle from the catheter.The needle may be withdrawn into a needle tip cover or needle cover thatextends over the needle's tip and prevents accidental needle sticks. Ingeneral, a needle tip cover includes a casing, sleeve, or other similardevice that is designed to trap/capture the needle tip when theintroducer needle is withdrawn from the catheter and the patient. Afterthe needle is withdrawn, the catheter is left in place to provideintravenous access to the patient.

The separation of the introducer needle assembly from the catheterportions of the catheter assembly presents numerous potential hazards tothe operators and others in the area. As indicated above, there is arisk of accidental needle sticks if the needle tip is not securedproperly in a needle tip shield. Additionally, because the needle hasbeen in contact with blood in the patient's vasculature, blood is oftenpresent on the needle's exterior as well as inside the lumen of theneedle. As the needle is withdrawn from the catheter, there is a riskthat this blood will drip from the needle tip or come into contact withother surfaces to expose people and equipment to blood. Additionally, ithas been observed that withdrawing a needle from a catheter assemblyoften imparts energy to the parts of the needle assembly. For instance,during needle withdrawal, bending forces can be applied (eitherunintentionally or intentionally) to the needle. Such energy has beenobserved to cause blood to splatter or spray from the needle when theneedle vibrates and shakes as it becomes free from the catheter assemblyand releases the stored energy.

The present disclosure discusses a bi-directional cannula featurecapture mechanism that allows a needle with a cannula feature to beretracted from an unshielded position to a shielded position in whichthe cannula feature is bi-directionally trapped. Accordingly, thedescribed capture mechanism is configured to lock the needle in theshielded position to significantly limit or prevent accidental sticksand blood exposure after the needle is withdrawn from a catheterassembly.

BRIEF SUMMARY OF THE INVENTION

The present application relates to a bi-directional cannula featurecapture mechanism that is designed to overcome some of the limitationsknown in the art. Typically, the capture mechanism comprises a cannulawith a cannula feature, an inner housing, an outer housing, and acatheter adapter. In some cases, when the cannula is in an unshieldedposition, the inner housing is received in the outer housing in a mannerthat allows the inner housing to translate proximally through the outerhousing. The cannula also extends axially through the inner housing andthe outer housing so that the cannula's distal tip extends past thedistal ends of both the inner and the outer housing. Additionally, inthe unshielded position, a distal portion of the cannula optionallyextends into a catheter and the outer housing is optionally coupled to acatheter adapter.

In some cases, when a proximal force retracts the cannula into ashielded position, the cannula translates proximally into the innerhousing until a feature on the cannula becomes bi-directionally engagedby the inner housing. In other words, the cannula feature movesproximally into the inner housing until the feature becomes trapped in amanner that restricts the cannula's proximal and distal movement andirreversibly locks the cannula in the shielded position.

As the proximal force on the cannula continues, the frictional forceexperienced between the cannula and the inner housing becomes greaterthan the frictional force experienced between the inner housing and theouter housing. As a result, the inner housing translates proximallythrough and becomes trapped in the outer housing. Once the cannulafeature is trapped by the inner housing and the inner housing is trappedby the outer housing so the cannula is shielded, the outer housing mayuncouple from the catheter adapter so the catheter can be used and thecannula/capture mechanism can be safely disposed.

The cannula may comprise any cannula that can be used with the describedcapture mechanism, including, but not limited to, a hypodermic needle,such as an IV catheter introducer needle. Additionally, the cannula maycomprise any component or characteristic that allows it to be used with,and be captured by, the described capture mechanism. In one example, thecannula comprises a bi-directionally engageable cannula feature, such asa notched crimp feature, a welded ferrule feature, a notch feature, acrimp feature, or another cannula feature that has an outer diameter(“OD”) that extends laterally past the OD of the cannula. In thisexample, the cannula feature comprises a proximal engagement and adistal engagement, which are adapted to contact corresponding surfacesin the inner housing to respectively restrict the cannula feature'sproximal and distal movement in the housing.

The inner housing may comprise any component or characteristic thatallows it to bi-directionally capture the cannula feature in a mannerthat limits the proximal and distal movement of the cannula when thecannula is in a shielded position. In one example, the inner housingcomprises an interior space through which the cannula extends axially.In another example, the inner housing comprises a proximal cannulafeature mating component that is adapted to contact the feature'sproximal engagement and stop the feature's proximal movement in thehousing. In still another example, inner housing comprises a distalcannula feature mating component that is adapted to contact the cannulafeature's distal engagement and stop the feature's distal movement afterthe feature has moved proximally past the distal mating component.

The outer housing may comprise a variety of suitable components orcharacteristics that allow the inner housing to slide proximally intothe outer housing. In some instances, the outer housing comprises acanister or a ring that is sized and shaped to receive the innerhousing. The outer housing can also be configured to be locked to theinner housing in a manner that prevents the inner housing from slidingdistally with respect to the outer housing when the cannula feature iscaptured by the proximal and distal mating components. For example, theouter housing may comprise a catch and corresponding interlock surface,a one-directional barb, or another retention feature that prevents theinner housing from moving distally in the outer housing, once thefeature has become bi-directionally captured.

The outer housing can be configured to selectively and removably coupleto any suitable catheter adapter, in any suitable manner. For example,the outer housing may comprise an interlock component that is biasedagainst a corresponding adapter interlock surface of the adapter whenthe cannula is in an unshielded position. In this example, the interlockcomponent is relaxed when the cannula is moved to a shielded position.Accordingly, the shielded cannula can be uncoupled from the catheteradapter and unintentional sticks can be prevented.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE FIGURES

In order that the manner in which the above-recited and other featuresand advantages of the invention will be readily understood, a moreparticular description of the bi-directional cannula feature capturemechanism briefly described above will be rendered by reference tospecific embodiments thereof, which are illustrated in the appendedFigures. Understanding that these Figures depict only typicalembodiments and are not, therefore, to be considered to be limiting ofits scope, the invention will be described and explained with additionalspecificity and detail through the use of the accompanying Figures inwhich:

FIG. 1 illustrates a partial cut-away plan view of a representativeembodiment of a catheter adapter comprising a bi-directional cannulafeature capture mechanism in which a catheter is disposed in anunshielded position;

FIGS. 2A-2E each illustrate a plan or perspective view of arepresentative embodiment of a suitable cannula feature;

FIG. 3A illustrates a partial cut-away plan view of a representativeembodiment of the bi-directional cannula feature capture mechanism inwhich the cannula tip is in the unshielded position;

FIG. 3B illustrates a partial cut-away plan view of a representativeembodiment of the bi-directional cannula feature capture mechanism inwhich the cannula tip is in a shielded position;

FIG. 4 illustrates a plan view of a portion of a partial cut-away viewof a representative embodiment of the bi-directional cannula featurecapture mechanism in which the cannula is in the shielded position;

FIGS. 5A, 5B, 6A, and 6B each illustrate a partial cut-away plan view ofa different embodiment of the bi-directional cannula feature capturemechanism in which the cannula is in the shielded position;

FIGS. 7A, 7B, 7C, 7D, and 7E illustrate a partial cut-away plan orperspective view of a representative embodiment of a method for usingthe bi-directional cannula feature capture mechanism;

FIG. 8 illustrates a partial cut-away plan view of a representativeembodiment of a catheter adapter in which interlock components areformed on the inner housing of the bi-directional cannula featurecapture mechanism; and

FIG. 9 illustrates a partial cut-away plan view of a representativeembodiment of a catheter adapter in which interlock components areformed on the inner and outer housings of the bi-directional cannulafeature capture mechanism.

DETAILED DESCRIPTION OF THE INVENTION

The presently preferred embodiments of the described invention will bebest understood by reference to the Figures, wherein like parts aredesignated by like numerals throughout. It will be readily understoodthat the components of the present invention, as generally described andillustrated in the Figures herein, could be arranged and designed in awide variety of different configurations. Thus, the following moredetailed description of the embodiments of the bi-directional cannulafeature capture mechanism, as represented in FIGS. 1 through 7E, is notintended to limit the scope of the invention, as claimed, but is merelyrepresentative of some presently preferred embodiments of the invention.

Generally, this application relates to a bi-directional cannula featurecapture mechanism. In other words, this application discusses a cannulafeature capture mechanism that allows a cannula with a feature to bemoved from an unshielded position to a shielded position in which thecannula feature is trapped and prevented from moving proximally anddistally out of the capture mechanism. As used herein, the term“unshielded” may refer to circumstances in which the cannula's distaltip is exposed from the capture mechanism. Conversely, the term“shielded” may refer to circumstances in which the cannula's tip iscovered, shielded, or otherwise protected. Because the capture mechanismallows the cannula to be locked in the shielded position, the capturemechanism may prevent unintended sticking and/or blood exposure. Tobetter explain the capture mechanism, a more detailed description of themechanism is given below, followed by a more detailed description of themechanism's use.

The capture mechanism can comprise any component or characteristic thatallows it to bi-directionally capture a cannula feature when the cannulais in the shielded position. For example, FIG. 1 shows a representativeembodiment in which the bi-directional cannula feature capture mechanism20 comprises a cannula (e.g., needle 40), a bi-directionally engageablecannula feature (e.g., needle feature 60), an inner housing 80, and anouter housing 100. Additionally, FIG. 1 shows that the capture mechanism20 can selectively be coupled with a catheter adapter 120. To provide abetter understanding of the capture mechanism 20, each of theaforementioned components is described in below in further detail.

FIG. 1 shows the capture mechanism 20 comprises a cannula (e.g., needle40). As used herein, the terms “cannula” and “cannulae” may refer tovirtually any rigid tube that is configured to be inserted into ananimal's body to draw off or to introduce fluid, wherein the tubecomprises a sharpened tip that allows the tube to puncture the body andaccess an intended space. Some examples of such cannulae comprisehypodermic needles and other cannulae that may expose their operator tothe risk of unintended sticking or blood exposure.

Where the cannula comprises a hypodermic needle, the cannula maycomprise any suitable type of hypodermic needle, including an introducerneedle for use in an IV catheter assembly (e.g., an over-the-needleperipheral IV catheter assembly). Indeed, according to some presentlypreferred embodiments, FIG. 1 shows the cannula comprises an introducerneedle 40.

The introducer needle may have any characteristic that is suitable foruse with an IV catheter assembly. By way of illustration, FIG. 1 showsan embodiment in which the introducer needle 40 comprises a sharpeneddistal tip 42, a lumen 44 (not directly shown), an elongated tubularportion 46 with a substantially constant outer diameter (“OD”) 48, and abi-directionally engageable needle feature 60. Additionally, each of theneedle's aforementioned components may comprise any suitablecharacteristic. For example, the distal tip of the needle may comprise astandard bevel, a short bevel, a true short bevel, a bias grind point, avet point, a lancet point, a deflected point (anti-coring), or anothersuitable needle point. In another example, the lumen and elongatedtubular portion may be any suitable size. For instance, the needle maybe any length or gauge (e.g., from a 7 to a 33 on the Stubs scale) thatallows it to be used as the introducer needle in an IV assembly.

Regarding the bi-directional needle feature, the needle may comprise anyneedle feature that is capable of being captured in the inner housing(as described below) in a manner that restricts the feature's distal andproximal movement within the inner housing. For instance, the featuremay comprise any suitable needle feature that has an OD that is greaterthan the needle's OD or has at least one surface that extends laterallypast the needle's OD. Indeed, in some embodiments, the feature comprisesone or more one-way barbs. Similarly, FIG. 2A shows that, in at leastone embodiment, the feature comprises a welded ferrule 62. FIG. 2B showsthat, in another representative embodiment, the feature comprises acrimp feature 64. FIGS. 2C and 2D show that, in still other embodiments,the feature comprises a crimp with a single notch 66 and a plurality ofnotches 68, respectively. However, FIG. 2E shows that in at least oneother embodiment, the feature comprises a notch 70.

Regardless of the specific type of needle feature, the feature may haveany suitable characteristic. For instance, the feature may be anysuitable shape or size. Similarly, the feature may include any suitablecomponent that allows the needle to function as intended and becomebi-directionally engaged when the needle is retracted to the shieldedposition. For instance, FIGS. 2A through 2E show that the various needlefeatures (e.g., 62, 64, 66, 68, and 70) comprise a proximal engagement72 and a distal engagement 74.

The needle feature's proximal engagement may have any suitablecharacteristic that allows the feature to be prevented from movingproximally out of the inner housing. For example, FIGS. 2A-2D show someembodiments in which a proximal side 76 of the features 62, 64, 66, and68 comprises a surface (e.g., proximal engagement 72) that extends pastthe needle's OD 48. In contrast, FIG. 2E shows a representativeembodiment in which the proximal engagement 72 comprises a surface thatextends from the needle's OD 48 towards a longitudinal axis 50 of theneedle 40, at a distal side 78 of the notch feature 70.

The needle feature's distal engagement may also have any suitablecharacteristic that allows the feature to be prevented from movingdistally out of the inner housing, once the needle has been moved intothe shielded position. For example, FIGS. 2A-2D show some embodiments inwhich a distal side 78 of the features 62, 64, 66, and 68 comprises asurface 74 that extends laterally past the needle's OD 48. On the otherhand, FIG. 2E illustrates a representative embodiment in which thedistal engagement 74 comprises a surface that extends axially from theneedle's OD 48, towards the needle's longitudinal axis 50, and at theproximal side 76 of the notch feature 70.

In some presently preferred embodiments, the needle feature comprisesnotched crimp feature (e.g., notched crimp feature 66 or 68). Indeed,such a feature may offer several advantageous characteristics. Forinstance, in addition to providing a surface that acts as the needle'sdistal engagement, the notch in the notched crimp feature may also serveother suitable purposes. For example, the notch may allow an operator tosee “flashback” when the catheter is placed in a patient's blood vessel.For instance, where the needle is placed within another device (e.g., acatheter) and the needle is inserted into a patient's vasculature, bloodflows through the needle's lumen, exits the lumen through the notch, andtravels between the outer diameter of the lumen and the inner diameterof the other device (e.g., a catheter). Accordingly, where the otherdevice is at least partially transparent, an operator may visualize asmall amount of blood and, thereby, confirm placement of the catheterwithin the patient's blood vessel. For a more detailed description ofsuitable notched crimp features and the advantages, see U.S. patentapplication Ser. No. 12/396,227, entitled Bi-directionally EngageableCannula Crimp Feature, filed Mar. 2, 2009, the entire disclosure ofwhich is hereby incorporated by reference.

As previously mentioned, the capture mechanism also comprises an innerhousing. The inner housing may comprise any suitable characteristic thatboth allows it to move proximally in the outer housing and allows theneedle feature to be retracted proximally until it becomesbi-directionally engaged. In one example of a suitable characteristic,the inner housing may be any suitable size or have any suitable shapethrough which the needle may axially pass. For instance, the innerhousing can be substantially cylindrical, cuboidal, tubular, etc.Indeed, FIG. 3A shows a cut-away view of a representative embodiment inwhich the inner housing 80 has a substantially cylindrical shape. Inanother example of a suitable characteristic, the inner housingcomprises a collet style housing that biases towards the needle as theinner housing translates proximally through the outer housing. By way ofillustration, FIG. 3A shows an embodiment in which the inner housing 80comprises a splayed housing that is split longitudinally down at leastone side.

The inner housing may also have any suitable component that allows it tobi-directionally engage the needle feature once the needle as beenretracted to the shielded position. For example, FIG. 3A shows the innerhousing 80 comprises inner walls 82, which define an interior space 84through which the needle 40 axially extends. In another example, FIG. 3Ashows the inner housing 80 comprises a proximal needle feature matingcomponent (“proximal mating component”) 84 and a distal needle featuremating component (“distal mating component”) 86.

The proximal mating component may comprise any suitable surface that isconfigured to contact needle feature's proximal engagement and preventthe feature from being proximally extracted out of the inner housing.For instance, the proximal mating component may comprise a needle port,one or more surfaces that extend axially from the inner walls, one ormore one-way barbs, or another surface that is adapted to contact thefeature's proximal engagement and prevent the feature from movingproximally past the surface. In one example, FIG. 3A shows the proximalmating component 84 comprises a needle port 88 that is sized and shapedto allow the needle 40, but not the notched crimp feature 66 with itssurfaces that extend laterally past the needle's OD (e.g., the proximalengagement 72), to pass therethrough. While FIG. 3A shows needle port 88may limit the proximal movement of the notched crimp feature 66 relativeto the inner housing 80, such a proximal mating component 84 may alsoact to limit the proximal movement of other needle feature's havinglaterally extending surfaces (e.g., features 62, 64, and 68 from FIG.2).

Where the proximal mating component comprises a needle port, the portmay have any suitable characteristic. For instance, the needle port maybe configured to wipe or squeegee fluids (e.g., blood) from the OD ofthe needle as the needle is pulled proximally through the needle port.This squeegee effect may be provided in any suitable manner. Forexample, the port may comprise a rubber, plastic, elastomeric, or othersimilar ring that is capable of wiping blood from the needle.Accordingly, the inner housing may further reduce the risk of bloodexposure.

In another example of a suitable proximal mating component (not shown),the proximal mating component comprises a surface that extends axiallyfrom the inner housing's inner walls (e.g., wall 82) and is configuredto extend towards the longitudinal axis of the needle. For instance, theproximal mating component may comprise a protuberance that is adapted toextend into a notch feature (e.g., notch feature 70 in FIG. 2E). In suchinstances, when the needle is moved to the shielded position, a distalside of the protuberance is adjacent to the notch's proximal engagement,so that when proximal force is applied to the needle, the protuberance'sdistal side contacts the proximal engagement to prevent the engagementfrom moving proximally respective to the inner housing.

The distal mating component may comprise any suitable surface that isconfigured to contact the needle feature's distal engagement and limitthe feature's distal movement respective to the inner housing after theneedle has been moved to the shielded position. For instance, the distalmating component may comprise one or more one-way barbs, one or moresurfaces that extend axially from the inner housing's inner walls,and/or another surface that is adapted to contact the feature's distalengagement and prevent the feature from moving distally after the needlehas been moved to the shielded position.

In one example, FIG. 3A shows the distal mating component 86 comprises asurface that extends axially from the inner wall 82 towards the needle40. In this example, once the distal engagement 74 translates proximallypast the distal mating component 86, the distal mating component isbiased towards the needle's OD 48, as shown in FIG. 3B. Accordingly, thedistal mating component 86 moves into a position that blocks thefeature's distal engagement 74 from moving distally when a distal forceis applied to the needle 40. While FIG. 3B shows the distal matingcomponent 86 is configured to mate with a notched crimp feature 66, sucha distal mating component 86 may also be used or modified to prevent thedistal movement of other features comprising a surface that extendslaterally past the needle's OD (e.g., needle features 62, 64, and 68).

In another example of a suitable distal mating component (not shown),the distal mating component comprises a surface (e.g., a protuberance)that extends axially from the inner housing's inner walls and isconfigured to extend into a notch feature (e.g., feature 70 in FIG. 2E)when the needle is in the shielded position. In this example, when theneedle is in the shielded position, a proximal side of the protuberanceis adjacent to the notch's distal engagement (e.g., 74). Thus, whendistal force is applied to the needle, the protuberance's proximal sidecontacts the distal engagement and prevents the engagement from movingdistally respective to the inner housing.

In addition to the previously mentioned components, the inner housingmay have any other suitable component that allows it to bi-directionallycapture the needle's feature and be used with a catheter assembly. Forinstance, the inner housing may comprise any suitable type of needleshielding component. By way of example, FIG. 3B shows the inner housing80 comprises needle shields 90 that extend distally past the distalmating component 86. While the needle shields 90 may have anycharacteristic that allows them to cover the needle 40 and protectpeople from unintentional sticking, FIG. 3B shows a representativeembodiment in which the needle shields 90 are long enough to extend pastthe needle's distal tip 42. Additionally, FIG. 3B shows the needleshields 90 optionally comprise transverse barriers 92 that provide aneedle tip capture mechanism that acts as a redundant needle capturemechanism and further encloses the needle tip 42 to reduce the risk ofblood exposure.

As previously mentioned, the capture mechanism comprises an outerhousing that is configured to receive the inner housing and allow theinner housing to translate proximally in the outer housing untilreaching an inner housing stop. The outer housing may have any suitablecharacteristic that allows the capture mechanism to operate as intended.In one example, FIG. 3A shows the outer housing 100 has an interiorspace 102 that is sized and shaped to receive the inner housing 80 in amanner that biases the distal end 104 of the outer housing 100 away theneedle 40 when the needle 40 is in the unshielded position. In anotherexample, FIG. 3B shows the outer housing 100 is sized and shaped toreceive the inner housing 80 in a manner that biases the inner housing80 towards the needle 40 when the needle 40 is in the shielded positionand the inner housing 80 has been moved proximally towards an innerhousing stop 106. As used herein, the term “inner housing stop” mayrefer to any suitable surface of the outer housing that is adapted tolimit the inner housing's proximal movement with respect to the outerhousing.

In still another example of a suitable characteristic of the outerhousing, the outer housing may be configured so that the friction forceexperienced between the inner housing and the outer housing is greaterthan the friction force experienced between the inner housing and theneedle until the needle's feature is captured by the distal and proximalmating component. In this example, when the needle is in the unshieldedposition and a proximal force is applied to it, the needle is allowed totranslate proximally into the inner housing without causing the innerhousing to translate proximally into the outer housing. However, oncethe feature's proximal engagement contacts the proximal matingcomponent, the frictional force between the needle and the inner housingis greater than the frictional force experienced between the innerhousing and the outer housing. Accordingly, as the proximal forcecontinues to be applied to the needle, the inner housing is caused totranslate proximally into the outer housing.

In some embodiments, the outer housing (and/or the inner housing)comprises means for locking the inner housing to the outer housing whenthe needle is in the shielded position. In such embodiments, the lockingmeans can comprise any suitable component or characteristic that allowsthe inner housing to translate proximally into the outer housing but notto reemerge distally. For instance, the outer housing and/or the innerhousing may include one or more one-way barbs, catches and correspondinginterlock surfaces, or other retention components that are capable oflocking the inner housing to the outer housing when the needled is inthe shielded position.

By way of example, FIG. 3B shows an embodiment in which the distal end104 of the outer housing 100 comprises a plurality of catches 108 thatact as locking means and seat against the distal end 94 of the innerhousing 80 to lock the inner housing 80 in place when the needle 40 isin the shielded position. In another example, FIG. 4 shows arepresentative embodiment in which the outer housing 100 comprisesplurality of catches 108 that are adapted to mate with correspondinginterlock surfaces 96 in the inner housing 80 when the needle 40 is inthe shielded position. In still another example, FIG. 5A shows arepresentative embodiment in which the outer housing 100 comprises aplurality of one-way barbs 110 that gouge into the inner housing 80 andprevent it from translating distally through the outer housing 100 oncethe needle 40 is shielded.

Where the outer housing is made of a material with a different level offlexibility than the inner housing, the differing flexibilities mayfurther help keep the two housings locked together after the needle hasbeen shielded. Thus, in some embodiments, the inner housing and theouter housing each comprise a material with a different level offlexibility. In one example, the outer housing comprises a firstmaterial that is less flexible than a second material of the innerhousing. For instance, the outer housing comprises a first material(e.g., a metal, a metal alloy, a ceramic, a hardened polymer etc.),while the inner housing comprises a more flexible material (e.g., aplastic, a polymer, etc.). In this example, the inner housing mayresiliently flex around catches, barbs, and/or other retention featuresin the outer housing as the inner housing moves proximally relative tothe outer housing. Additionally, in this example, the outer housingrigidly supports the inner housing after the inner housing has beenmoved proximally into the outer housing.

In another example, however, the outer housing comprises a firstmaterial that is more flexible than the second material of the innerhousing. For example, the outer housing may comprise a plastic while theinner housing comprises a metal. In this example, the outer housing mayresiliently flex as the inner housing translates distally through theouter housing.

In some embodiments, the distal mating component and the distalengagement are configured so that once the needle is moved into theshielded position, a distal force on the needle causes the distalengagement to press against the distal mating component in a manner thatcauses the inner housing to expand radially. This radial expansion, inturn, causes the inner housing to further bind in the outer housing andprevents the inner housing from moving distally with respect to theouter housing. This radial expansion can be accomplished in any suitablemanner. For example, the feature's distal engagement (e.g., 74) and/orthe inner housing's distal mating component (e.g., 86) may be sloped orotherwise configured to cause the inner housing to radially expandwithin the outer housing when a distal force is applied to the needle.

As mentioned above, in some embodiments, the capture mechanism is usedwith a catheter adapter. Indeed, the capture mechanism may be used withany suitable catheter adapter. Generally, FIG. 5A shows the catheteradapter 120 comprises a proximal end 122 and a distal end 124 with alumen 126 extending between the two. FIG. 5A also shows that theproximal end 122 of the adapter 120 is configured to receive the capturemechanism 20 so the outer housing 100 can be coupled within theadapter's lumen 126. Although not shown in FIG. 5A, the skilled artisanwill recognize that the adapter's distal end 124 can comprise a catheterwith an inner diameter that is slightly larger than the outer diameterof the needle 40. Accordingly, in the unshielded position, the needle'stip 42 can extend distally past the adapter's distal end 124.

Where the capture mechanism is used in conjunction with a catheteradapter, the two can be coupled in any suitable manner that allows thecapture mechanism to be coupled to the adapter when the needle is in theunshielded position and to be uncoupled from the adapter when the needleis in the shielded position. In one example of a suitable couplingmechanism, the outer housing comprises an interlock component that mateswith a corresponding adapter interlock surface in the lumen of theadapter. In another example of a coupling mechanism, however, the outerhousing comprises an adapter interlock surface that corresponds with aninterlock component disposed within the adapter lumen.

Where the outer housing is selectively coupled within the catheteradapter by a coupling mechanism, the coupling mechanism may be locatedin any suitable position. For example, FIG. 5A shows a representativeembodiment in which the adapter interlock surface 128 is locateddistally within the adapter's lumen 126. Furthermore, FIG. 5A shows thedistal end 104 of the outer housing 100 is flared, bent, or otherwisecomprises interlock component 112 that is suitable to mate with theinterlock surface 128. In another example, however, FIG. 5B shows arepresentative embodiment in which the adapter interlock surface 128 isdisposed proximally within the lumen 126 and the corresponding interlockcomponent 112 is disposed near a proximal end 114 of the outer housing100.

Where the outer housing is selectively coupled to the inner housing witha coupling mechanism comprising an interlock component and acorresponding adapter interlock surface, the coupling mechanism mayfunction in any suitable manner. In one example, when the needle is inthe unshielded position, the inner housing is splayed open in a mannerthat applies pressure to the distal end of the outer housing. In thisexample, the pressure from the inner housing causes interlock components(e.g., 112) at the distal end of the outer housing to be biased againstcorresponding interlock surfaces (e.g., 128) within the adapter's lumen.In another example, FIG. 5A shows that when the needle 40 is moved tothe shielded position and the inner housing 80 is moved proximally intothe outer housing 100, the interlock components 112 at the distal end104 of the outer housing 100 are relaxed so the capture mechanism 20with the shielded needle 40 can be safely uncoupled from the adapter120.

In another example of how the coupling mechanism may work, the couplingmechanism may be configured so that the frictional force experiencedbetween the interlock component and the adapter interlock surface isgreater than the frictional force experienced between the inner housingand the outer housing and between the needle and the inner housing untilthe needle has been moved to the shielded position and the inner housinghas moved adjacent to the inner housing stop. Accordingly, once theneedle's feature has become bi-directionally engaged within the innerhousing and the inner housing has become locked with the outer housing,additional proximal force, above the frictional force experiencedbetween the interlock component and the adapter interlock surface, willcause the capture mechanism and shielded needle to become uncoupled fromthe adapter.

FIG. 8 illustrates an example where the interlock components 112 areformed on the inner housing 80 rather than the outer housing 100. Insuch cases, the interlock components 112 can be formed at any positionof the outer surface of the inner housing 80 that is exposed to theinner surface of the adapter's lumen prior to the needle being shielded.Similarly, the interlock surfaces 128 can be formed in an appropriatelocation within the adapter's lumen so that when the interlockcomponents 112 are inserted into the interlock surfaces 128, the capturemechanism is appropriately positioned within the lumen. Then, when theneedle 40 is retracted into the inner housing 80, the distal end of theinner housing 80 contracts radially inward causing the interlockcomponents 112 to separate from the interlock surfaces 128 therebyfreeing the capture mechanism to be uncoupled from the adapter.

FIG. 9 illustrates an example where the interlock components 112 a, 112b are formed on both the inner housing 80 and the outer housing 100. Insuch cases, corresponding interlock surfaces 128 a, 128 b can be formedin appropriate locations within the adapter's lumen. Accordingly thecapture mechanism can be configured in various different ways tointerlock with the adapter.

In addition to the previously described embodiments of thebi-directional needle feature capture mechanism, the capture mechanismmay be modified in any suitable manner that allows it to fulfill itsintended purpose. For instance, while FIG. 5B shows an embodiment inwhich the distal ends 94 and 104 of both the inner housing 80 and theouter housing 100, respectively, extend past the needle's distal tip 42,in other embodiments, only the distal end of the outer housing or innerhousing extend past the needle's distal tip when the needle is in theshielded position. For instance, FIG. 6A shows a representativeembodiment in which only the outer housing 100 is configured to shieldthe needle's tip 42 when the proximal engagement surface 72 contacts theproximal mating component 84 and the needle's tip 42 is moved proximallypast the outer housing's distal end 104. In contrast, FIG. 6B shows arepresentative embodiment in which only the inner housing 80 isconfigured to extend distally past and shield the needle's tip 42 whenthe feature's proximal engagement surface 72 contacts the innerhousing's proximal mating component 84.

In another example of how the capture mechanism can be modified, FIG. 6Bshows the that instead of comprising a canister-like object (as shown inFIG. 6A), the outer housing 100 may simply include a ring-like structurethat is adapted to receive the inner housing 80.

The described bi-directional needle feature capture mechanism can beused in any suitable manner. By way of non-limiting illustration, FIG.7A shows that before the needle 40 is inserted into a patient's bloodvessel (not shown), the needle 40 extends axially through the inner 80and outer 100 housings and through the distal tip 124 of the catheteradapter 120. Additionally, FIG. 7A shows that before the needle 40 isinserted into the blood vessel, the needle's feature 66 is disposeddistal to the inner housing's distal end 94. Moreover, FIG. 7A shows theinner housing 80 is disposed within the outer housing 100, distal to theinner housing stop 106.

After the needle 40 has been inserted into the blood vessel, FIGS. 7Band 7C show the needle 40 is withdrawn proximally into the inner housing80 while the position of the inner housing 80 relative to the outerhousing 100 remains substantially unchanged. Once the feature's proximalengagement 72 contacts the proximal mating component 84, FIG. 7D showsthe inner housing 80 moves proximally with respect to the outer housing100 until reaching the inner housing stop 106. Finally, FIG. 7E showsthat once the needle 40 is irreversibly locked in the capture mechanism20, the outer housing 100 can be pulled proximally so as to uncouplefrom the adapter 120. Accordingly, the operator may use the catheter andsafely dispose of the needle.

The described capture mechanism and associated methods may offer severaladvantages over certain prior art needle shielding devices. For example,because the described capture mechanism captures the needle's feature,the mechanism does not require transverse barrier tip protection.Instead, as described above, the mechanism may include transversebarrier tip protection as a redundant safety feature to provide enclosedneedle point coverage. In another example, because the capture mechanismcaptures the needle's feature primarily, and not the needle's tip, thecapture mechanism may be relatively compact. This compact design mayallow the entire capture mechanism to be contained within the lumen ofthe catheter adapter. Additionally, the compact design may allow thecapture mechanism to be inexpensive to manufacture and to incorporateadditional components, such as conventional or novel valvingtechnologies for post-activation blood control.

The present invention may be embodied in other specific forms withoutdeparting from its structures, methods, or other essentialcharacteristics as broadly described herein and claimed hereinafter. Thedescribed embodiments and examples are to be considered in all respectsonly as illustrative, and not restrictive. The scope of the inventionis, therefore, indicated by the appended claims, rather than by theforegoing description. All changes that come within the meaning andrange of equivalency of the claims are to be embraced within theirscope.

The invention claimed is:
 1. A catheter device, comprising: abi-directional cannula feature capture mechanism comprising: an innerhousing, wherein the inner housing comprises an elastomeric material,wherein the inner housing comprises a proximal cannula feature matingcomponent and a distal cannula feature mating component; a catheteradapter; an outer housing, wherein the outer housing comprises amaterial that is less flexible than the elastomeric material, wherein aninner surface of the outer housing comprises at least oneproximally-facing barb that gouges into the elastomeric material of theinner housing to thereby prevent the inner housing from translatingdistally through the outer housing while allowing the inner housing totranslate proximally through the outer housing; and a cannula thatextends into the inner housing, wherein the cannula comprises a distaltip and a cannula feature, wherein the cannula feature comprises aproximal engagement surface and a distal engagement surface, whereinwhen the cannula is retracted proximally within the inner housing, theproximal engagement surface contacts the proximal cannula feature toprevent the cannula feature from moving proximally out of thebi-directional cannula feature capture mechanism and the distal cannulafeature mating component prevents the distal tip from moving distallyout of the bi-directional cannula feature capture mechanism, therebyshielding the distal tip within the bi-directional cannula featurecapture mechanism.
 2. The catheter device of claim 1, wherein the distalcannula feature mating component contacts the distal engagement surfaceto prevent the distal tip from moving distally out of the bi-directionalcannula feature capture mechanism.
 3. The catheter device of claim 1,wherein the distal cannula feature mating component contacts the distaltip to prevent the distal tip from moving distally out of thebi-directional cannula feature capture mechanism.
 4. The catheter deviceof claim 1, wherein, when the proximal engagement surface contacts theproximal cannula feature, the inner housing is positioned proximal tothe at least one proximally-facing barb.
 5. The catheter device of claim4, wherein the material that is less flexible than the elastomericmaterial comprises metal.
 6. The catheter device of claim 1, wherein theinner housing forms a needle port through which the cannula extends, theneedle port also being formed of the elastomeric material to therebywipe blood from the cannula as the cannula moves proximally through theneedle port.